Hello! I need help with a rainwater drainage problem. Not sure what to do in this situation: the terraced house has a rear extension that is the width of the back garden (about 5 m). The length of the back garden is 9m. Currently the rainwater is siphoned into a raised bed. I wanted to put a soakaway in, but it's clay soil. Also supposed to be 2.5 m from boundary - the garden width is 5m. Where else can the water go? There's no other pipework it can attach to, no drain. All I can guess is that the extension covers the original surface water drain. Thanks